Preparation And Property Of Biomineralized Coatings On The Titanium Alloy After Two Kinds Of Treatment

Titanium alloys are widely used as the implants in the biomedical field owing to their excellent physicochemical propertites and biocompatibility in the human environment. However, due to their bioinert, titanium alloys can not bond with bone firmly. With similar chemical composition and crystallographic structure to that of bone mineral, Hydroxyapatite (HA) can directly bond to bones. Therefore, HA coatings are commonly used to improve the osteoinductivity of the titanium alloy. However, to improve long-term stability of implants, some treatments should be performed to enhance the combination between titanium alloy implant and human tissue.In this thesis, two chemical techniques of acid-alkali-combination method (AAC) and polydopamine-assisted self-assembly technique were employed to induce bioactive HA coatings on the surface of titanium alloy by immersing in SBF. Surface morphologies, changes of surface compositions, and structural analysis of the formed HA coatings on titanium alloy were investigated by characterizations of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). After that, the synthesized HA coatings were evaluated by co-culture experiments with MC3T3-E1osteoblasts in order to validate their cytocompatibility. The main results are drawn as follows:1) Two different acid-alkali systems were firstly used to treat the surface of titanium alloy. By SEM observation, it is seen that the surface topography of titanium alloy is different and a uniform porous network structure formed on titanium alloy by acid-alkali-combination method (AAC). Then, HA coating was easily formed on the surface of titanium alloy treated by immersing in SBF. In addition, the osteoblasts culture test indicated that the adhesion ability and cell proliferation of osteoblasts on the HA coating was higer than those of the control group.2) Self-assembly technique was firstly used to prepare polydopamine thin film on the surface of titanium alloy. Then, carbon-containing HA coating was easily formed on polydopamine coated titanium alloy by immersing in SBF, which was confirmed by characterizations of SEM, XRD, and FTIR. In addition, the early adhesion and proliferation of osteoblasts were increased on the biomineralizated coatings treated by polydopamine than the untreated. This polydopamine-assisted biomineriation technique may have great potential in biomedical applications.